Hydroprocessing with a catalyst having a narrow pore size distribution

ABSTRACT

A catalyst useful for hydroprocessing a hydrocarbon-containing oil contains at least one hydrogenation component on an amorphous, porous refractory oxide. The catalyst is prepared by impregnating support particles having a narrow pore size distribution and a mode pore diameter from abpit 70 to 80 angstroms with a solution containing a precursor of the hydrogenation components, followed by drying and calcining. The catalyst is useful for promoting a number of hydrocarbon hydroprocessing reactions, particularly hydrogenative desulfurization, dedemetallization and denitrogenation, and most particularly, hydrodesulfurization of residuum-containing oils.

This application is a division of Ser. No. 213,079 filed June 9, 1988,now U.S. Pat. No. 4,886,582.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to hydrocarbon hydroprocessing catalysts, such asthose utilized to catalyze the reaction of hydrogen withorgano-nitrogen, organo-metallic and particularly organo-sulfurcompounds. More particularly this invention is directed to a catalystuseful for the hydrodesulfurization of hydrocarbons, such as residuumoils, and to a method for preparing such catalysts by employing anaqueous impregnating solution with porous, amorphous refractory oxidesupport particles. The invention is especially directed to catalysts ofhigh overall desulfurization activity.

2. Description of the Prior Art

In the refining of hydrocarbons, it is often necessary to convert ahydrocarbon-containing oil fraction to different forms. Typically,particulate catalysts are utilized to promote desulfurization,denitrogenation or demetallization reactions when feedstocks such asresiduum-containing oils are contacted with catalysts under conditionsof elevated temperature and pressure and in the presence of hydrogen sothat the sulfur components are converted to hydrogen sulfide, thenitrogen components to ammonia and the metals are deposited on thecatalyst.

Hydroprocessing of hydrocarbon-containing oils may be carried out with acatalyst containing Group VIB and Group VIII hydrogenation metals on arefractory oxide support. Compositions containing these and otherelements have been previously prepared by comulling and impregnationmethods. For example, catalysts useful for hydroprocessingresiduum-containing oils comprising a Group VIB metal, particularlymolybdenum or tungsten, and a Group VIII metal, particularly cobalt ornickel, on an alumina base have been disclosed in U.S. Pat. Nos.3,980,552, and 4,460,707. In U.S. Pat. No. 3,980,552, a catalyst havingan average pore diameter between 40 and 100 angstroms is prepared bycomulling precursors of the hydrogenation metals with those of thesupport materials. The catalyst in U.S. Pat. No. 4,460,707 has anaverage pore diameter greater than about 180 angstroms and is preparedby impregnation, that is, by deposition of the active components on thesupport base by contact thereof with an aqueous solution containing thehydrogenation components in dissolved form. Such catalysts have beenpreviously effective for removing contaminant metals and sulfur fromresiduum-containing oils.

Although conventional catalysts are active and stable for hydrocarbonhydroprocessing reactions, catalysts of yet higher activities andstabilities are still being sought. Increasing the activity of acatalyst increases the rate at which a chemical reaction proceeds undergiven conditions, and increasing the stability of a catalyst increasesits resistance to deactivation, that is, the useful life of the catalystis extended. In general, as the activity of a catalyst is increased, theconditions required to produce a given end product, such as ahydrocarbon of given sulfur, nitrogen, and/or contaminant metalscontent, become more mild. Milder conditions require less energy toachieve the desired product, and catalyst life is extended due to suchfactors as lower coke formation or the deposition of less metals.

SUMMARY OF THE INVENTION

Briefly, the invention provides for a catalyst useful forhydroprocessing hydrocarbon-containing oils and a method for preparingsuch a catalyst employing an impregnating solution and porous refractoryoxide support particles having a narrow pore size distribution wherein amode pore diameter is in the range from about 65 to about 85 angstroms.In one embodiment, a catalyst obtained from impregnation of such supportparticles contains at least one metal hydrogenation component in anamount less than 15 weight percent (calculated as a trioxide) supportedon the amorphous, porous refractory oxide. The catalyst has a pore sizedistribution wherein (1) at least 75 percent of the total pore volume isin pores of diameter from about 20 angstroms above to about 20 angstromsbelow a mode pore diameter in the range from 70 to 90 angstroms, (2) atleast 3 percent to less than 10 percent of the total pore volume is inpores of diameter greater than 110 angstroms, and (3) less than 10percent of the total pore volume is in pores of diameter less than 60angstroms.

In a preferred embodiment, a hydroprocessing catalyst is prepared by themethod of impregnating alumina-containing support particles having anarrow pore size distribution with an aqueous impregnating solutioncomprising a dissolved molybdenum component and a dissolved nickel orcobalt component, followed by calcination. In this embodiment thecatalyst contains about 10 to about 14 weight percent of molybdenumcomponents (as MoO₃) and about 0.01 to about 6 weight percent of cobaltor nickel components (calculated as the monoxide) and has porositycharacteristics including at least 80 percent of the total pore volumein pores of diameter from about 20 angstroms above or below a mode porediameter of 75 to 90 angstroms and about 7 to about 10 percent of thetotal pore volume in pores of diameter greater than 110 angstroms.

Catalysts prepared in accordance with the invention are useful forpromoting the hydroprocessing of hydrocarbon-containing oils, andparticularly for hydrodesulfurizing residuum-containing oils. A catalystprepared with the support particulates described above exhibits highactivity when utilized to promote high conversions of organo-sulfurcompounds, particularly those found in hydrocarbon residuum-containingoils, to hydrogen sulfide.

DETAILED DESCRIPTION OF THE INVENTION

The invention is directed to a catalyst, usually a catalyst useful forhydroprocessing a hydrocarbon-containing oil. The catalyst isparticularly well suited for hydrodesulfurization of aresiduum-containing oil. The catalyst typically contains up to 15 weightpercent of at least one active metal hydrogenation component (calculatedas the metal al trioxide), ordinarily a metal component selected fromthe group consisting of Group VIB metals and Group VIII metals on anynumber of non-zeolitic support particles comprising a porous, amorphousrefractory oxide.

Support particles suitable for use herein include such porous amorphousrefractory oxides as silica, magnesia, silica-magnesia, zirconia,silica-zirconia, titania, silica-titania, alumina, silica-alumina,lithium-alumina, phosphorus-alumina, lithium-phosphorus-alumina, etc.,with supports containing alumina being highly preferred. Supportscontaining gamma alumina are the most highly preferred, particularlythose supports containing at least 90, and even more preferably at least95 weight percent of gamma alumina. Preferred support particles havingthe preferred physical characteristics disclosed herein are commerciallyavailable from Nippon-Ketjen Catalyst Division of AKZO-Chemie, andAmerican Cyanamid, Inc. Mixtures of the foregoing refractory oxides arealso contemplated, especially when prepared as homogeneously aspossible.

The amorphous, porous refractory oxide support material is usuallyprepared in the form of shaped particulates, with the preferred methodbeing to extrude a precursor of the desired support through a die havingopenings therein of desired size and shape, after which the extrudedmatter is cut into extrudates of desired length. The precursor may be arefractory oxide gel such as a spray-dried or peptized alumina gel. Thesupport particles may also be prepared by mulling (or pulverizing) apre-calcined porous refractory oxide to a particle size less than about100 microns and extruding the material. Also, the support particles maybe prepared by extruding a combination of precursor gel and mulledpre-calcined porous refractory oxide in a weight ratio in the range fromabout 1:20 to about 20:1

The support particles prepared in the form of gel extrudates aregenerally pre-calcined prior to impregnation, especially if gammaalumina is the desired support material. Temperatures above about 900°F. are usually required to convert (calcine) the precursor of thedesired support to the porous, amorphous refractory oxide form, as forexample, the conversion of alumina gel to gamma alumina Usually,temperatures above about 1,100° F. are utilized to effect thistransformation, with holding periods of one-half to three hoursgenerally being utilized to produce preferred gamma alumina extrudates

The extruded particles may have any cross-sectional shape, i.e.,symmetrical or asymmetrical, but most often have a symmetricalcross-sectional shape, preferably a cylindrical or polylobal shape. Thecross-sectional diameter of the particles is usually about 1/40 to about1/8 inch, preferably about 1/32 to about 1/12 inch, and most preferablyabout 1/24 to about 1/15 inch. Among the preferred catalystconfigurations are cross-sectional shapes resembling that of athree-leaf clover, as shown, for example, in FIGS. 8 and 8A of U.S. Pat.No. 4,028,227. Preferred clover-shaped particulates are such that each"leaf" of the cross-section is defined by about a 270° arc of a circlehaving a diameter between about 0.02 and 0.05 inch. Other preferredparticulates are those having quadralobal cross-sectional shapes,including asymmetrical shapes, and symmetrical shapes such as in FIG. 10of U.S. Pat. No. 4,028,227. Other particulates are available fromDavison Chemical Company, a division of W. R. Grace & Company, havingring and monolith shapes, as disclosed in U.S. Pat. No. 4,510,261.

An impregnating solution containing at least one hydrogenation componentprecursor may be utilized to incorporate the catalytically activehydrogenation components with any of the amorphous, porous refractorysupport particles. A variety of the preferred Group VIB metal componentsmay be utilized to produce a stable impregnating solution. In general,all Group VIB metal compounds soluble in aqueous media, particularlythose of molybdenum or tungsten, may be utilized. The oxides ofmolybdenum (e.g., molybdenum trioxide) are preferred, as are many saltscontaining molybdenum, particularly precursors of molybdenum trioxide.Also useful are salts containing both a Group VIB metal and ammoniumion, such as ammonium dimolybdate, and most preferably ammoniumheptamolybdate. Suitable Group VIII metal compounds are water-soluble,and usually include an oxide, carbonate, and preferably a nitrate ofcobalt, nickel, and iron, or combinations thereof. The nitrates ofcobalt and nickel are preferred. Preferably, the final solution containsGroup VIII components (as the monoxide) in a total concentration betweenabout 0.01 and 10 weight percent and more preferably about 1 to about 6weight percent. Although not usually remaining on the final catalystcomposition, citric acid may often be employed in the impregnatingsolution in combination with the hydrogenation components, andparticularly when the pH of the impregnating solution is less than 1.0.

Several methods may be employed to impregnate the catalytic supportparticles with an impregnating solution. One such method, commonlyreferred to as the spray impregnation technique, involves spraying thesupport with the impregnating solution. Another impregnating method,often used to maintain relatively low concentrations of hydrogenationcomponents in the solution, is the circulation or multi-dip procedurewherein the support is repeatedly contacted with the impregnatingsolution with or without intermittent drying Preferred methods, however,require soaking the support in an impregnating solution or circulatingthe support therein, as for example, the pore volume or pore saturationtechnique, the continuous solution impregnation (CSI) technique and thelike. The pore saturation method involves dipping the catalyst supportinto an impregnating solution having a volume usually sufficient to fillthe pores of the support and, on occasion, may be up to about 10 percentexcess. The concentrations of hydrogenation components in the solutionduring impregnation by this technique may be somewhat higher than thoseutilized in other methods because the ratios of hydrogenation componentsin the final catalyst are determined directly by solution composition.

The amounts of active hydrogenation components retained on the supportparticles during impregnation will depend largely on physicalcharacteristics of the support particles, inter alia, surface area, porevolume and pore size distribution. Broadly speaking, the supportparticles have a surface area of about 10 to about 400 m² /gram andtypically above 100 m² /gram, and preferably about 125 m² /gram to about400 m² /gram (as measured by the B.E.T. method). The total pore volumeof the amorphous support, as measured by conventional mercuryporosimeter methods, is usually about 0.35 to about 0.8 cc/gram,preferably about 0.4 to about to about 0.7 cc/gram, and most preferablybetween about 0.45 and about 0.7 cc/gram.

Physical characteristics of the support particles utilized to preparethe catalyst of the invention, as determined by conventional mercuryporosimeter testing methods, typically include a narrow pore sizedistribution wherein at least 75, preferably at least 80, and mostpreferably at least 85 percent of the total pore volume is in pores ofdiameter from about 20 angstroms below the mode pore diameter to about20 angstroms above the mode pore diameter. On a pore volume basis, thesupport ordinarily has at least about 0 35 cc/gram, preferably at leastabout 0.4 cc/gram, and most preferably at least about 0.45 cc/gram ofthe total pore volume in pores of diameter from about 20 angstroms belowthe mode pore diameter to about 20 angstroms above the mode porediameter. Also, the support usually has at least 60 percent, andpreferably at least 65 percent of the total pore volume in pores ofdiameter from about 10 angstroms above the mode pore diameter to about10 angstroms below the mode pore diameter. On a pore volume basis, atleast 0.6 cc/gram and preferably at least 0.65 cc/gram of the total porevolume is in pores of diameter from 10 angstroms above to 10 angstromsbelow the mode pore diameter. The mode pore diameter, as referred toherein, is the pore diameter represented on a pore size distributioncurve of a support or catalyst at which the derivative of the total porevolume (cc/g.) plotted on the ordinate vs. the pore diameter (angstroms)plotted on the abscissa is a maximum. The mode pore diameter of thesupport particles usually lies in the range from about 65 to about 85angstroms and preferably from 70 to 85 angstroms.

An unusual feature of the pore size distribution of the support is theamount of total pore volume in pores of diameter greater than about 110angstroms. The support ordinarily has at least about 4 percent, or, inthe alternative, usually at least about 0.025 cc/gram of the total porevolume in pores of diameter greater than 110 angstroms, yet does notcontain more than about 10 percent of the total pore volume in pores ofdiameter greater than 110 angstroms. Also, the support contains lessthan 15 percent, preferably less than 12 percent, or, in thealternative, less than about 0.085 cc/gram and preferably less than 0.08cc/gram, of the total pore volume in pores of diameter less than 60angstroms. Physical characteristics of two preferred amorphousrefractory oxide supports utilized in preparation of catalysts of theinvention are summarized in Table I as follows:

                  TABLE I                                                         ______________________________________                                        Pore                                                                          Diameter     Support N     Support M                                          Angstroms    cc/gram  % PV     cc/gram                                                                              % PV                                    ______________________________________                                        <40          0        0        0      0                                       40-50        0.002    0.3      0.019  3.5                                     50-60        0.026    4.1      0.059  10.9                                    60-70        0.112    17.5     0.195  35.9                                    70-80        0.378    59.0     0.178  32.8                                    80-90        0.083    13.0     0.037  6.8                                      90-100      0.003    0.5      0.005  0.9                                     100-110      0.004    0.6      0.007  1.3                                     >110         0.032    5.0      0.043  7.9                                     PORE VOLUME  0.640             0.543                                          cc/gram                                                                       (Merc. Poros.)                                                                MODE PORE    73                70                                             DIAMETER, Å                                                               (Merc. Poros.)                                                                SURFACE AREA 300               290                                            m.sup.2 /gram                                                                 (B.E.T. method)                                                               ______________________________________                                    

After impregnation, the support is dried and calcined to produce acatalyst containing the hydrogenation components in desired proportions.Calcination is usually at a temperature of at least 700° F., andpreferably from about 750° F. to about 1,400° F., so as to convert thehydrogenation metals to their oxide forms. However, impregnated supportparticles containing a significant portion of nickel are calcined at atemperature preferably less than about 1000° F., although supportparticles containing significant amounts of cobalt may preferably becalcined up to about 1,400° F. Furthermore, when calcining supportparticles impregnated with a solution containing a Group VIII metallicnitrate, flowing air is usually passed at a sufficient rate over thesupport particles to remove the nitrogen oxide NO and NO₂ produced bythe reactions associated with nitrate component decomposition.

The final composition of the catalyst of the invention contains at leastone metal hydrogenation component on the support particles. The physicalcharacteristics of the final catalyst composition will usually vary fromthose of the support particles by less than about 25 percent. The finalcomposition generally contains less than 15 weight percent, and usuallyin the range from about 1 to about 15 weight percent, of at least onemetal hydrogenation component, calculated as the metal trioxide. Apreferred catalyst contains a Group VIB metal component and/or a GroupVIII metal component, usually in the range from about 10 to about 14weight percent calculated as the trioxide, and about 1 to about 6 weightpercent, calculated as the monoxide, respectively. The preferred GroupVIB metal components include molybdenum and tungsten, with molybdenumthe most highly preferred. The preferred Group VIII metal componentsinclude cobalt and nickel. Another component which may be included inthe catalyst is a phosphorus component, usually in an amount from about0.01 to about 1 weight percent, calculated as P.

In accordance with the invention, a catalyst is prepared so as to have anarrow pore size distribution wherein at least 75 percent, or, in thealternative, at least 0.35 cc/gram of the total pore volume is in poresof diameter from about 20 angstroms below the mode pore diameter toabout 20 angstroms above the mode pore diameter. The mode pore diameteris usually in the range from about 70 to about 90 angstroms, less thanabout 10 percent of the total pore volume is contained in pores ofdiameter less than 60 angstroms, and about 3 to about 10 percent of thetotal pore volume is contained in pores of diameter greater than 110angstroms. Furthermore, the catalyst may have a pore size distributionwherein at least 80 percent of the total pore volume is in pores ofdiameter from about 20 angstroms below the mode pore diameter to about20 angstroms above the mode pore diameter, less than 10 percent of thetotal pore volume is in pores of diameter less than 60 angstroms andgreater than about 4 percent to less than about 10 percent of the totalpore volume is in pores of diameter greater than 110 angstroms. Physicalcharacteristics of the catalyst of the invention including pore sizedistribution, mode pore diameter (mpd) surface area and total porevolume are summarized in Table II.

                  TABLE II                                                        ______________________________________                                        Physical Characteristics of Catalyst                                          Pore Size                                                                     Distribution                                                                  Diameter in                                                                              % of Total Pore Volume                                             Angstroms  Broad      Preferred                                                                              Most Pref.                                     ______________________________________                                         <60       <10         <9       <7                                            >110        >3         4-10     5-10                                           50-100    >75        >85      >90                                            mpd ± 20                                                                              >75        >80      >85                                            mpd ± 10                                                                              >50        >55      >60                                             >90       >10        >12      >14                                            >100        >5         >6       >7                                            mpd        70-90      75-90    75-85                                          ______________________________________                                    

The total pore volume of the final catalyst of the invention preferablyis greater than 0.45 cc/gram. On a pore volume basis, ranges of porositycharacteristics of such preferred catalysts are summarized in Table IIA.

                  TABLE IIA                                                       ______________________________________                                        Physical Characteristics of Catalyst                                          Pore Size                                                                     Distribution                                                                  Diameter in                                                                              cc/gram of Total Pore Volume                                       Angstroms  Broad      Preferred                                                                              Most Pref.                                     ______________________________________                                         <60       <0.055     <0.050   <0.046                                         >110       >0.014     >0.015   >0.023                                         50-100     >0.34      >0.37    >0.40                                          mpd ± 20                                                                              >0.34      >0.39    >0.42                                          mpd ± 10                                                                              >0.20      >0.25    >0.28                                           >90       >0.03      >0.06    >0.07                                          >100       >0.01      >0.03    >0.04                                          ______________________________________                                    

One of the unusual features of the catalyst of the invention is thecombination of the following porosity characteristics: (1) a substantialamount of pore volume within both 10 and 20 angstroms from a mode porediameter in the range from 70 to 90 angstroms, (2) a relatively smallamount of pore volume, i.e., less than 10 percent, in pores of diameterless than 60 angstroms, and (3) a significant amount of pore volume inpores of diameter greater than 110 angstroms, i.e., at least 3 percent,and preferably at least about 7 percent (or greater than 0.030 cc/gram)up to about 10 percent of the total pore volume. It is theorized, atleast for hydrodesulfurization purposes, that minimizing the number ofminipores (60 angstrom diameter or smaller) and maximizing the number ofmacropores (110 angstrom diameter or larger) up to a limit of about 10percent of the total pore volume contributes to available surface areain pores of diameter allowing sulfur-containing molecules to penetrateinto the catalyst; the invention, however, is not limited to this or anyother theory of operation.

After calcination, the final catalyst is generally activated byconventional means for its intended use in a given hydroprocess of ahydrocarbon-containing oil. The catalyst may, for example, be activatedby reduction of the metal hydrogenation components to the free metalform, employed in the calcined oxide form or converted from the oxideform to the sulfide form. When employed with active components in thesulfide form, the catalyst may be presulfided so as to convert theactive metal components to the corresponding sulfides. Usually thecatalysts are presulfided prior to use by contact with a stream ofsulfiding gas, such as hydrogen sulfide-hydrogen mixtures containingabout 1 to 10 volume percent of hydrogen sulfide, at temperaturesbetween about 200° F. and 1,200° F. Although presulfiding of thecatalyst is preferred, it is not essential, as the catalyst may besulfided "in situ" in a short time by contact with a sulfur-containingfeedstock processed under hydroprocessing conditions.

The catalyst of the invention may be employed in any of severalprocesses for hydroprocessing hydrocarbon containing oils whereincatalytic composites containing Group VIB and/or Group VIII metals areknown to be catalytically effective, such as hydrogenation,dehydrogenation, hydrodesulfurization, oxidation, hydrodenitrogenation,hydrodemetallization cracking, mild hydrocracking, hydroreforming, andthe like. Contemplated for treatment by the process of the invention arerelatively high boiling hydrocarbon-containing oils including crudepetroleum oils and synthetic crudes. Among the typical oils contemplatedare top crudes, vacuum and atmospheric residual fractions, light andheavy atmospheric and vacuum distillate oils, deasphalted oils, shaleoils, and oils from bituminous sands, coal compositions and the like.For use herein, typical hydrocarbon-containing oils, or mixturesthereof, may contain at least about 10 volume percent of componentsnormally boiling above about 1050° F. and in some cases, at least 20volume percent Other hydrocarbon-containing oils include lubricatingoils, waxes, kerosene, solvent naphthas, fuel oils, diesel fuels, jetfuels, heavy naphthas, light naphthas, cycle oils from crackingoperations, coker distillates, cracked gasoline, decant oils, and thelike.

Although virtually any high boiling hydrocarbon-containing feedstock maybe treated by hydroprocessing with the catalyst of the invention, theprocess is particularly suited to treating residuum-containing oils,i.e., heavy residual fractions, especially the atmospheric and vacuumresiduum oils containing at least about 2 ppmw of contaminant metals(vanadium, nickel, and the like). Sulfur is usually present in such oilsin a proportion exceeding 0.1 weight percent and often exceeding 1.0weight percent. A particularly preferred proportion of sulfur is about 1to about 8 weight percent. The feedstock contains undesirableproportions of nitrogen, usually in a concentration greater than about 2ppmw and often between about 2 ppmw and 5000 ppmw. Ordinarily thefeedstock contains less than 200 ppmw of nickel and vanadium contaminantmetals, calculated as Ni plus V, with preferred feedstocks containingless than 100 ppmw and most preferably less than 50 ppmw of saidmaterials. The feedstock may contain waxy components, e.g., n-paraffinsand slightly-branched paraffins, and thus have a high pour point, e.g.,at least about 30° F.

The catalyst may be employed as either a fixed, ebullating, slurried orfluidized bed (but most usually a fixed bed) of particulates in asuitable reactor vessel wherein the hydrocarbon oil to be treated isintroduced and subjected to hydroprocessing conditions including anelevated total pressure, temperature, and hydrogen partial pressure.Under such conditions, the hydrocarbon oil and catalyst are subjected toa hydrogen partial pressure usually in the range from about 100 to about4,000 p.s.i.g. at a space velocity usually in the range from about 0.05to about 20 LHSV so as to effect the desired degree of hydroprocessing,as for example, demetallization, desulfurization and/or denitrogenation,i.e., so as to effect the desired degree of conversion of, for example,sulfur, nitrogen and metal-containing compounds to hydrogen sulfide,ammonia, and metal forms capable of being deposited in the catalyst,respectively. The catalyst of the invention is particularly effectivefor desulfurization, denitrogenation and demetallization reactions,especially when utilized to process hydrocarbon oils such as residuumfractions.

In the hydroprocessing of a hydrocarbon oil, the catalyst is usuallymaintained in a hydroprocessing reactor as a fixed bed with thefeedstock passing downwardly once therethrough. In some instances, oneor more additional reactors may be added to the single reactor, eitherin series or parallel. If the feedstock is unusually high inorganometallic compounds, it may be pretreated, integrally orseparately, using a conventional hydrodemetallization catalyst or ahydrodemetallization catalyst of the invention and particularly, ahydrodemetallization catalyst having a substantial amount of pore volumein pores of diameter greater than that corresponding to the mode porediameter of the catalyst of the invention.

Typical hydroprocessing conditions that are suitable forhydrodenitrogenation, hydrodesulfurization, or that yield less thanabout 10 volume percent conversion of the oil fraction boiling above1050° F. to liquid products boiling at or below 1050° F., are shown inthe following Table III:

                  TABLE III                                                       ______________________________________                                        Operating Conditions                                                                          Suitable Range                                                                            Preferred Range                                   ______________________________________                                        Temperature, °F.                                                                       500-900     600-850                                           Hydrogen Pressure, p.s.i.g.                                                                     200-4,000   500-2,500                                       Space Velocity, LHSV                                                                          0.05-5.0    0.1-3.0                                           Hydrogen Recycle Rate,                                                                          500-15,000                                                                               1,000-10,000                                     scf/bbl                                                                       ______________________________________                                    

Generally, the hydrogen partial pressure maintained duringhydroprocessing is more than 50 percent of the total pressure. Usually,for once-through operation, the hydrogen partial pressure is betweenabout 85 and 95 percent of the total pressure while, for recycleoperation, the hydrogen partial pressure is somewhat lower, i.e.,between 80 and 85 percent of the total pressure.

The hydroprocess of the invention may include either serial orsimultaneous desulfurization and denitrogenation of a feedstock.Simultaneous desulfurization, denitrogenation and heavy component (1050°F. plus components) conversion, as used herein, involves contacting ahydrocarbon-containing feedstock with the particulate catalyst disclosedherein under conditions effecting (1) a lower sulfur and nitrogencontent in the effluent and (2) a higher percentage of liquid productsboiling at or below 1050° F. in the effluent as compared to thefeedstock. Serial desulfurization and denitrogenation of a feedstock bycontact with the catalyst of the invention involves removing sulfur andnitrogen from the feedstock either prior to or after contact of thefeedstock with a catalyst effective for removing a substantialproportion of contaminant metals from the feed.

A preferred embodiment utilizing the catalyst of the invention comprisesa combined hydrodemetallation, hydrodesulfurization andhydrodenitrogenation reaction zone wherein the catalyst of the inventionis located in a downstream portion of a fixed bed relative to anupstream catalyst bed portion containing a demetallation catalyst havingan average pore diameter of at least 30 angstroms greater than that ofthe catalyst of the invention. In contrast to utilizing a comparableconventional narrow pore sized catalyst in the downstream location ofthe catalyst bed, the catalyst of the invention exhibits better activityfor removing nitrogen, sulfur, and conversion of 1050° F.+ components to1050° F.- components in the hydrocarbon-containing feed.

The invention is further illustrated by the following examples which areillustrative of specific modes of practicing the invention and are notintended as limiting the scope of the invention as defined in theappended claims.

EXAMPLE I

Catalysts A and B, prepared in accordance with the invention, are testedunder typical hydrodesulfurization conditions against a commercialhydrodesulfurization catalyst, Catalyst X. Catalysts A, B and X have a1/20 inch trilobal cross-sectional shape and have nominal compositionsof 12.0 weight percent of molybdenum components, calculated as MoO₃, and3.0 weight percent of cobalt components, calculated at CoO, and thebalance of gamma alumina. Catalysts A and B of the invention areprepared as follows:

An impregnating solution of the invention is prepared by placing 23.74grams of ammonium heptamolybdate (AHM) in a beaker containing 45 ml ofwater. With vigorous stirring, 18.78 grams of citric acid (monohydrate)is added, and all of the solids are dissolved. Cobalt nitrate(Co(NO₃)₂.6H₂ O) in the amount of 18.59 grams is then dissolved in theresulting solution. After dissolution of the cobalt nitrate, animpregnating solution having a volume of 88 ml is prepared. Theprocedure is repeated to produce two impregnating solutions having thesame final volume.

Two 125 gram portions of gamma alumina support particles M (preparationof Catalyst A) and N (preparation of Catalyst B), having pore sizedistributions as shown in Table I herein, are then contacted with theimpregnating solution. Substantially all 88 ml of each impregnatingsolution is taken up by each of the supports.

The impregnated composition is allowed to stand (age) for two hoursfollowing which it is oven dried at 110° C. and then calcined at 1,022°F. for 1/2 hour in flowing air. The final catalysts of the invention,Catalysts A and B, and conventional Catalyst X, have pore sizedistributions as shown in Table IV.

                  TABLE IV                                                        ______________________________________                                        PORE SIZE DISTRIBUTIONS AND SURFACE AREAS                                     Pore                                                                          Diameter,   Catalyst X Catalyst A Catalyst B                                  Angstroms   P.V.    %      P.V.  %     P.V. %                                 ______________________________________                                         <40        0       0      0     0     0    0                                 40-50       0.006   1.2    0.002 0.9   0.007                                                                              1.3                               50-60       0.054   10.5   0.033 6.3   0.016                                                                              3.1                               60-70       0.132   25.8   0.095 18.3  0.037                                                                              7.1                               70-80       0.160   31.3   0.204 39.2  0.098                                                                              18.9                              80-90       0.105   20.5   0.110 21.2  0.284                                                                              54.6                               90-100     0.027   5.3    0.026 5.0   0.035                                                                              6.7                               100-110     0.013   2.5    0.009 1.7   0.013                                                                              2.5                               >110        0.015   2.9    0.041 7.9   0.030                                                                              5.8                               TOTAL PORE  0.512          0.520       0.520                                  VOLUME                                                                        (Merc. Poros.)                                                                MODE PORE   74             76          84                                     DIAMETER, Å                                                               (Merc. Poros.)                                                                SURFACE AREA                                                                              293            215         210                                    m.sup.2 /gram                                                                 (B.E.T. method)                                                               ______________________________________                                    

The test is conducted by contacting the catalysts in separate runs withthe feedstock identified in Table V under hydroprocessing conditions.However, at the outset of each run, the respective catalysts arepresulfided by contact for about 16 to 20 hours with a gas consisting of90 volume percent H₂ and 10 volume percent H₂ S flowing at 4.4 SCFM (oneatmosphere pressure). The temperature during the presulfiding isinitially at room temperature, is increased gradually until 700° F. isreached, and then lowered to 450° F., at which time the catalyst iscontacted with the feedstock.

                  TABLE V                                                         ______________________________________                                        Feedstock Properties                                                          ______________________________________                                        Feed Description                                                                              Kuwait Atmospheric Resid                                      ______________________________________                                        Gravity, °API                                                                          16.8                                                          Sulfur, wt. %   3.7                                                           Total Nitrogen, wt. %                                                                         0.270                                                         Asphaltenes (C.sub.5), wt. %                                                                  6.9                                                           Nickel, ppmw    14                                                            Vanadium, ppmw  49                                                            ______________________________________                                        ASTM D-1160, Vol. %                                                                           Distillation, °F.                                      ______________________________________                                        IBP/5           487/610                                                       10/20           664/739                                                       30/40           805/868                                                       50/60            937/1028                                                     max.            1108                                                          rec.            73.0                                                          ______________________________________                                    

A portion of the feedstock is passed downwardly through a reactor vesseland contacted in separate runs with Catalyst A and Catalyst X, in asingle-stage, single-pass system with once-through hydrogen Theoperating conditions during each run are summarized as follows: 1,480p.s.i.g. total pressure, 0.5 LHSV, a hydrogen rate of 4,100 SCF/bbl, andan initial temperature of 720° F.

Giving Catalyst X employed at 15 days in the reference hydroprocess anarbitrary activity of 100, relative activities of Catalysts A and B ofthe invention and Catalyst X for denitrogenation and desulfurization aredetermined by calculation and tabulated in comparison to Catalyst X inTable IV. These desulfurization activity determinations are based on acomparison of the reaction rates for desulfurization obtained from thedata of the experiment according to the following standard equationwhich assumes second order kinetics for desulfurization: ##EQU1## whereS_(fr) and S_(pr) are the respective concentrations of sulfur in thefeed and product obtained with the reference catalyst and S_(f) andS_(p) are the respective concentrations of sulfur in the feed andproduct obtained with a catalyst being compared to the reference.

The relative volume activity (RVA) for sulfur conversion obtained foreach catalyst is set forth in Table VI. The data in Table VI indicatethat Catalysts A and B prepared from an impregnant solution and supportparticles having the indicated porosity are more active (i.e., at leastabout 10 percent) than the commercial catalyst.

                  TABLE VI                                                        ______________________________________                                                      RVA for                                                                       sulfur                                                                 Catalyst                                                                             removal, S                                                      ______________________________________                                               A      133                                                                    B      112                                                                    X      100                                                             ______________________________________                                    

EXAMPLE II

Catalyst A of Example I and another catalyst, Catalyst C, are tested inseparate runs for hydroprocessing the feedstock of Example I under thesame conditions as Example I.

Catalyst C is prepared in the same manner and with the same supportparticles as Catalyst A in Example I, except the AHM and cobalt amountsare reduced.

The dried and calcined finished catalyst has a nominal composition asset forth in Table VII.

                  TABLE VII                                                       ______________________________________                                                                      RVA for                                                                       sulfur                                          Catalyst MoO.sub.3     CoO    removal, S                                      ______________________________________                                        A        12.0          3.0    133                                             C        9.6           2.4    104                                             ______________________________________                                    

The data in Table VII indicate that Catalyst C, containing less cobaltand molybdenum components than Catalyst A in Example I, is less activefor desulfurization than Catalyst A in Example I.

EXAMPLE III

Catalyst A of Example I and two other catalysts, Catalysts D and E, aretested in separate runs for hydroprocessing the feedstock of Example Iunder the same conditions as Example I.

Catalysts D and E are prepared in the same manner and with the samesupport particles as Catalyst A in Example I, except: (1) in thepreparation of Catalyst D, 21.62 grams of AHM are added to 25 ml ofwater and the resulting solution mixed with 28.5 ml of 28% ammoniumhydroxide (NH₄ OH) solution and 24 ml of nickel nitrate solutioncontaining 17.16 grams (Ni(NO₃.6H₂ O) thereof; and (2) in thepreparation of Catalyst E, 23.47 grams of AHM are added to 45 ml ofwater and the resulting solution mixed with 10.12 grams of 85 percentphosphoric acid (H₃ PO₄) to dissolve the AHM and 18.59 grams of cobaltnitrate (Co(NO₃)₂.6H₂ O) is then dissolved therein.

The dried and calcined finished catalysts each have a nominalcomposition as set forth in Table VIII.

                  TABLE VIII                                                      ______________________________________                                                                         RVA for                                                                       sulfur                                       Catalyst  MoO.sub.3                                                                             CoO        P   removal, S                                   ______________________________________                                        A         12.0    3.0        --  133                                          D         12.0    3.0        --  111                                                            (NiO)                                                       E         12.0    3.0        2.9 115                                          ______________________________________                                    

The data in Table VI indicate that Catalyst D, containing nickel andmolybdenum components, and Catalyst E, containing cobalt, molybdenum andphosphorus components, both prepared from the same support particles asCatalyst A in Example I, are active for desulfurization of residuumcontaining feedstocks.

While particular embodiments of the invention have been described, itwill be understood, of course, that the invention is not limited theretosince many obvious modifications can be made, and it is intended toinclude within this invention any such modifications as will fall withinthe scope of the invention as defined by the appended claims.

I claim:
 1. A catalytic hydroprocess of a hydrocarbon-containing oilcontaining nitrogen or sulfur, said hydroprocess comprising contacting acatalytic composition with said hydrocarbon-containing oil underhydroprocessing conditions so as to produce a producthydrocarbon-containing oil containing less nitrogen or sulfur than saidhydrocarbon-containing oil, said catalytic composition consistingessentially of at least one cobalt metal hydrogenation component and atleast one molybdenum hydrogenation metal component supported on anamorphous, porous refractory oxide, said composition having a pore sizedistribution wherein at least 75 percent of the total pore volume is inpores of diameter from about 20 angstroms below the mode pore diameterto about 20 angstroms above the mode pore diameter, less than 10 percentof said total pore volume is in pores of diameter less than 60 angstromsand greater than 3 percent to less than 10 percent of said total porevolume is in pores of diameter greater than 110 angstroms, said modepore diameter of said composition is in the range from about 70 to about90 angstroms.
 2. The process defined in claim 1 wherein saidhydrocarbon-containing oil comprises a residuum hydrocarbon feed.
 3. Theprocess defined in claim 1 wherein said hydrocarbon-containing oilfurther comprises contaminant metals.
 4. The process defined in claim 3wherein said hydrocarbon-containing oil contains less than 100 ppmw ofsaid contaminant metals, calculated as Ni plus V.
 5. The hydroprocessdefined in claim 1 wherein at least 80 percent of the total pore volumeis in pores of diameter from about 20 angstroms below the mode porediameter to about 20 angstroms above the mode pore diameter.
 6. Thehydroprocess defined in claim 1 wherein greater than about 0.34 cc/gramof the total pore volume is in pores of diameter from about 20 angstromsabove the mode pore diameter to about 20 angstroms below the mode porediameter.
 7. The hydroprocess defined in claim 1 wherein greater thanabout 0.39 cc/gram of the total pore volume is in pores of diameter fromabout 20 angstroms above the mode pore diameter to about 20 angstromsbelow the mode pore diameter.
 8. The hydroprocess defined in claim 1wherein greater than about 75 percent of the total pore volume is inpores of diameter from about 50 angstroms to about 100 angstroms.
 9. Thehydroprocess defined in claim 1 wherein greater than 85 percent of thetotal pore volume is in pores of diameter from about 50 to about 100angstroms.
 10. The hydroprocess defined in claim 1 wherein greater thanabout 50 percent of the total pore volume is in pores of diameter fromabout 10 angstroms below the mode pore diameter to about 10 angstromsabove the mode pore diameter.
 11. The hydroprocess defined in claim 1wherein greater than about 55 percent of the total pore volume is inpores of diameter from about 10 angstroms below the mode pore diameterto about 10 angstroms above the mode pore diameter.
 12. The hydroprocessdefined in claim 1 wherein greater than 0.34 cc/gram of the total porevolume is in pores of diameter from about 50 to about 100 angstroms. 13.The hydroprocess defined in claim 1 wherein greater than about 0.37cc/gram of the total pore volume is in pores of diameter from about 50to about 100 angstroms.
 14. The hydroprocess defined in claim 1 wherein5 to 10 percent of said total pore volume is in pores of diametergreater than 110 angstroms.
 15. The hydroprocess defined in claim 1wherein about 7 to about 10 percent of said total pore volume is inpores of diameter greater than 110 angstroms.
 16. The hydroprocessdefined in claim 1 wherein greater than 0.015 cc/gram of said total porevolume is in pores of diameter greater than 110 angstroms.
 17. Thehydroprocess defined in claim 1 wherein greater than about 0.023 cc/gramof said total pore volume is in pores of diameter greater than 110angstroms.
 18. The hydroprocess defined in claim 1 wherein greater thanabout 0.030 cc/gram of said total pore volume is in pores of diametergreater than 110 angstroms
 19. The hydroprocess defined in claim 1wherein less than about 0.055 cc/gram of said total pore volume is inpores of diameter less than 60 angstroms.
 20. The hydroprocess definedin claim 1 wherein greater than about 12 percent of said total porevolume is in pores of diameter greater than 90 angstroms.
 21. Thehydroprocess defined in claim 1 wherein said mode pore diameter is from75 to 90 angstroms.
 22. The hydroprocess defined in claim 1 whereingreater than about 0.03 cc/gram of said total pore volume is in pores ofdiameter greater than 100 angstroms.
 23. The hydroprocess defined inclaim 1 wherein greater than about 0.06 cc/gram of said total porevolume is in pore a of diameter greater than 90 angstroms.
 24. Thehydroprocess defined in claim 1 prepared by a method comprising the stepof impregnating calcined, amorphous, porous refractory oxide supportparticulates with at least one precursor of said hydrogenation metalcomponent, said calcined, amorphous, porous refractory oxide supporthaving a pore size distribution wherein at least 80 percent of the totalpore volume is in pores of diameter from about 20 angstroms above themode pore diameter to about 20 angstroms below the mode pore diameterand at least about 4 to less than about 10 percent of the total porevolume is in pores of diameter greater than 110 angstroms, said modepore diameter of said support is in the range from about 65 to about 85angstroms.
 25. The hydroprocess defined in claim 24 wherein said supporthas a total pore volume from about 0.4 to about 0.8 cc/gram.
 26. Thehydroprocess defined in claim 24 wherein a total pore volume is fromabout 0.4 to about 0.7 cc/gram.
 27. A catalytic hydroprocess of ahydrocarbon-containing oil containing contaminant metals, nitrogen orsulfur, said hydroprocess comprising contacting a catalytic compositionwith said hydrocarbon-containing oil under hydroprocessing conditions soas to produce a product hydrocarbon-containing oil containing lessnitrogen, sulfur or contaminant metals than contained in saidhydrocarbon-containing oil, said catalytic composition consistingessentially of about 0.01 to about 6 weight percent of cobalt metalhydrogenation components, calculated as the monoxide, and about 1 toabout 15 weight percent of molybdenum metal hydrogenation components,calculated as the trioxide, supported on an amorphous, porous refractoryoxide containing alumina, said composition having a pore sizedistribution wherein at least 80 percent of the total pore volume is inpores of diameter from about 20 angstroms below the mode pore diameterto about 20 angstroms above the mode pore diameter, less than 10 percentof said total pore volume is in pores of diameter less than 60 angstromsand about 4 percent to less than 10 percent of said total pore volume isin pores of diameter greater than 110 angstroms, said mode pore diameteris in the range from about 70 to about 90 angstroms.
 28. Thehydroprocess defined in claim 27 consisting essentially of about 10 toabout 14 weight percent of said molybdenum hydrogenation components,calculated as MoO₃, and about 2 to about 5 weight percent of said cobalthydrogenation components, calculated as CoO.
 29. The hydroprocessdefined in claim 27 wherein said mode pore diameter is from 75 to 90angstroms.
 30. The hydroprocess defined in claim 27 wherein greater than0.03 cc/gram of said pore volume is in pores of diameter greater than110 angstroms.
 31. The hydroprocess defined in claim 27 wherein lessthan 0.05 cc/gram of said pore volume is in pores of diameter less than60 angstroms.
 32. The hydroprocess defined in claim 31 wherein saidamorphous, porous refractory oxide consists essentially of alumina. 33.The hydroprocess defined in claim 27 wherein at least about 0.40 cc/gramof said pore volume is in pores of diameter from about 50 to about 100angstroms and at least about 0.035 cc/gram is in pores of diameter than100 angstroms.
 34. The hydroprocess defined in claim 27 wherein at leastabout 55 percent of said total pore volume is in pores of diameter fromabout 10 angstroms above to about 10 angstroms below the mode porediameter and greater than 12 percent of said total pore volume is inpores of diameter greater than 90 angstroms.
 35. The hydroprocessdefined in claim 27 prepared by a method comprising the step ofimpregnating calcined, amorphous, porous refractory oxide supportparticulates with at least one precursor of said cobalt component and atleast one precursor of said molybdenum components, said supportparticulates having a pore size distribution wherein at least 80 percentof the total pore volume is in pores of diameter from about 20 angstromsabove the mode pore diameter to about 20 angstroms below the mode porediameter and greater than about 4 percent to less than 10 percent of thetotal pore volume is in pores of diameter less than 110 angstroms, saidmode pore diameter of said support particulates is in the range fromabout 65 to about 85 angstroms.
 36. The hydroprocess defined in claim 35wherein said support particulates have a total pore volume from about0.45 to about 0.7 cc/gram.
 37. The hydroprocess defined in claim 27wherein greater than 5 percent of said total pore volume is in pores ofdiameter greater than 110 angstroms.
 38. A process for catalyticallyhydroprocessing a hydrocarbon-containing oil wherein the catalyticcomposition is contacted with a hydrocarbon-containing oil underhydroprocessing conditions to produce a product hydrocarbon-containingoil containing hydrogenated components of said hydrocarbon-containingoil, said catalytic composition consisting essentially of about 10 toabout 14 weight percent of molybdenum hydrogenation components,calculated as MoO₃, about 2 to about 5 weight percent of cobalthydrogenation components, calculated as the monoxide, and supported on aporous, amorphous refractory oxide consisting essentially of alumina,said composition having a pore size distribution wherein at least 80percent of the total pore volume is in pores of diameter from about 20angstroms above the mode pore diameter to about 20 angstroms below themode pore diameter, less than 10 percent of said total pore volume is inpores of diameter less than 60 angstroms and greater than 4 percent toless than 10 percent of said total pore volume is in pores of diametergreater than 100 angstroms, said mode pore diameter of said compositionis in the range from about 70 to about 90 angstroms.
 39. The processdefined in claim 38 wherein said hydrocarbon-containing oil comprises aresiduum hydrocarbon oil containing sulfur and said hydroprocessingconditions comprise hydrodesulfurization conditions and saidhydrogenated components comprise hydrogen sulfide.
 40. The processdefined in claim 38 wherein greater than 5 percent of said total porevolume is in pores of diameter greater than 110 angstroms.
 41. Theprocess defined in claim 38 wherein at least about 7 percent of saidtotal pore volume is in pores of diameter greater than 110 angstroms.42. The process defined in claim 38 wherein at least 85 percent and atleast 0.40 cc/gram of said total pore volume is in pores of diameterfrom about 50 to about 100 angstroms.
 43. The process defined in claim38 wherein said mode pore diameter is from 75 to 90 angstroms and atleast 12 percent of said total pore volume is in pores of diametergreater than 90 angstroms.